Devices and methods for percutaneous mitral valve repair

ABSTRACT

Devices and methods are provided for diagnosing and repairing mitral valve defects such as mitral valve regurgitation. According to an exemplary method, mitral valve function is visualized by transesophageal echocardiography. A catheter ( 10 ) is inserted along the venous system of the patient through the left and right atria (a, b) into the mitral valve ( 26 ). A suction tip ( 25 ) grasps the leaflets ( 28, 30 ) of the mitral valve ( 26 ) to immobilize and juxtapose the leaflets ( 28, 30 ) at a point simulating a stitch, and the mitral valve ( 26 ) is again observed to confirm that fastening at that point will repair the prolapse or other defect. The mitral valve leaflets ( 28, 30 ) are then fastened together via a fastener such as a staple ( 44 ) or shape memory rivet ( 44 ). The fastener ( 44 ) may be inserted by a stapling assembly ( 40 ) in the catheter ( 10 ), or by a separate stapler ( 40 ) that is inserted along an arterial path from the opposite direction and guided along a transcardiac rail to the immobilized point. Upon completion of the repair process, the mitral valve ( 26 ) is once again visualized by transesophageal echocardiography to determine whether repair thereof has been effected.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not Applicable.

FIELD OF THE INVENTION

The invention relates generally to cardiac treatment devices andtechniques, and in particular, to methods and devices for diagnosis andrepair of mitral valve defects such as mitral valve regurgitation.

BACKGROUND OF THE INVENTION

The mitral valve is one of four heart valves that direct blood throughthe two sides of the heart. The mitral valve itself consists of twoleaflets, an anterior leaflet and a posterior leaflet, each of which arepassive in that the leaflets open and close in response to pressureplaced on the leaflets by the pumping of the heart.

Among the problems that can develop or occur with respect to the mitralvalve is mitral valve regurgitation (MR), in which the mitral valveleaflets become unable to close properly, thus causing leakage of themitral valve. Severe mitral regurgitation is a serious problem which, ifleft untreated, can adversely affect cardiac function and thuscompromise the patient's quality of life and life-span.

Currently, mitral regurgitation is diagnosed by many indicators, and themechanism of mitral regurgitation can be accurately visualized bytransesophageal echocardiography. The most prevalent and widely acceptedcurrent technique to correct mitral regurgitation is to repair themitral valve via open heart surgery while a patient's heart is stoppedand the patient is on cardiopulmonary bypass, a highly invasiveprocedure that has inherent risks.

Nonetheless, this invasive technique for repairing mitral regurgitationis currently favored because it allows for complete visualization of themitral valve without the accompanying distraction and disruption of abeating heart, and because it is believed to allow for repair of themitral valve with an unmatched degree of certainty and accuracy.Non-surgical, percutaneous repair of the mitral valve is not currentlyutilized because of the perceived difficulty of effecting repair of themitral valve while the heart is not arrested, and because of the limitedamount of space in and around the mitral valve in which to route arepair device or devices.

Accordingly, it would be desirable to provide a less invasive yetequally effective procedure for repairing a mitral valve.

It also would be desirable to provide a procedure for diagnosticmanipulation of the mitral valve in order to effectuate mitral valveregurgitation repair.

SUMMARY OF THE INVENTION

These and other desirable objects are attained by a catheter system andcatheterization procedure of the present invention, wherein a catheteris configured for percutaneous access to the atrium along the venoussystem of a patient, and for subsequent positioning of the catheter inbetween the mitral valve leaflets. The tip of the catheter has astructure defining suction or reverse flow directed radially into thecatheter on opposite sides thereof. The catheter suction system capturesthe rapidly moving leaflets of the mitral valve while the heart isnon-arrested such that functioning of the heart is uninterrupted andunaffected. The captured mitral valve leaflets are immobilized andjuxtaposed to each other in a small region at the suction catheter tip,simulating an Alfieri mitral valve stitch as discussed in the article ofFucci, C. et al. in European Journal of Cardio-thoracic Surgery, 9(1995), pages 621-7 and in the article of Maisano, F. et al. in EuropeanJournal of Cardio-thoracic Surgery, 13 (1998), pages 240-246.Preferably, simultaneous transesophageal echocardiography (TEE) providesvisualization of the catheter tip placement, confirmation of theimmobilization of the mitral valve leaflets and determination of theeffectiveness of subsequent stitch position on mitral valve leakage. Afastener such a staple or a shape memory rivet is then placed in thejuxtaposed immobilized leaflets to effect the repair of the mitralvalve. This repair technique should be particularly effective when themechanism of mitral regurgitation (MR) is mitral valve prolapse or flailof a mitral leaflet.

In one embodiment of the present invention, the catheter includes anextendable guide wire assembly. Once the mitral valve leaflets arecaptured via suction from the catheter, the guide wire is advancedforward from a distal tip of the catheter into the ventricle and asecond percutaneous assembly is advanced via an arterial route tocapture the end of the guide wire and to draw the guide wire out fromthe heart to guide an endovascular stapler. The stapler is then advancedalong the guide wire into position at the immobilized leaflets to staplethe leaflets together from the opposite side.

In additional embodiments of the present invention, the catheterassembly itself may apply a fastener from the a trial side. Thisfastener may be a wire rivet having shape memory coils that assume aform to effect permanent fastening. Particular coil configurations mayspread their ends, or may shorten a middle portion to draw capturedtissue flaps together, or both. In one of these embodiments, a smallballoon or diverter body at the tip of the catheter defines lateralsuction paths for effectively positioning the captured leaflets and alsoserves to direct the fastener through the opposed leaflets. The balloonis then deflated such that the flaps are drawn together and the fastenercan reassume its memory shape. In another of these embodiments, ahelical shape memory coil fastener carried in the catheter tip isejected such that it winds through the opposed leaflets with its axisparallel to the plane of the junction.

In any of the embodiments of the present invention, a separate lumen orsmall pressure chamber at the tip may apply a glue or cement between thecaptured leaflets to further stabilize the junction.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a perspective view of a suction catheter in accordance with anembodiment of the present invention;

FIG. 2 is a top view of the mitral valve and the suction catheter inaccordance with the present invention;

FIG. 2A is a schematic view in vertical section of the suction catheterpositioned in the heart;

FIG. 3 is a top view of the mitral valve, the suction catheter and astapling device in accordance with the present invention;

FIG. 4 is a top view of the mitral valve during the stapling process;

FIG. 5 is a side view of the mitral valve during the stapling process;

FIG. 6 is a side view, with partial cut away, of the stapling catheterof FIGS. 3-5 during the stapling process;

FIG. 7 is a side view of the mitral valve leaflets following thestapling process;

FIG. 8 is a top view of the mitral valve following the stapling process;

FIG. 9 is a top view of a shape memory fastener deployment system of thepresent invention;

FIG. 10 is a side view, with partial cut away, of the catheter of FIG. 9

FIG. 11 is a side view, with partial cut away, of the catheter of FIGS.9-10 during deployment of the shape memory fastener;

FIG. 12 is a side view, with partial cut away, of the catheter of FIGS.9-10 following deployment of the shape memory fastener;

FIG. 13 is a side view of the mitral valve leaflets following thedeployment of the shape memory fastener of FIGS. 9-12;

FIG. 14 is a top view of the mitral valve following deployment of theshape memory fastener of FIGS. 9-12.

FIG. 15 is a side view, with partial cut away, of an alternateembodiment of the shape memory fastener deployment system of FIGS. 9-14;

FIGS. 16-17 are side views, each with partial cut away, of the system ofFIG. 15 during two stages of the deployment of a shape memory fastener;

FIG. 18 is a side view of the mitral valve leaflets following deploymentof the shape memory fastener of FIGS. 15-17;

FIG. 19 is a top view of the mitral valve following deployment of theshape memory fastener of FIGS. 15-18;

FIG. 20 is a side view, with partial cut away, of another alternateembodiment of the shape memory fastener deployment system of the presentinvention;

FIG. 21 is a top perspective view of the system of FIG. 20 duringdeployment of a shape memory fastener;

FIG. 22 is a side view, with partial cut away, of the system of FIG. 20during deployment of a shape memory fastener; and

FIG. 23 is a top view of a mitral valve following deployment of theshape memory fastener of FIGS. 20-23.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring initially to FIG. 1, a catheter 10 for use with the presentinvention to repair mitral valve regurgitation is shown. Catheter 10 hasa proximal end 12 and a distal end 14 and is sized and shaped asgenerally known in the art to travel within and along the vascular treeto the heart of a patient. The catheter 10 has at least one opening ator near its distal end 14 in which suction force or reverse flow may bedrawn. An exemplary suction catheter 10 has at least one opening 16, 18respectively on each of the anterior surface 20 and the posteriorsurface 21 of a suction tip region 25 of the catheter. In a preferredembodiment, the anterior surface 20 and the posterior surface 21 of thetip region 25 of the catheter each have one large opening 16, 18. Thetip region 25 of the catheter is depicted in FIG. 1 as being shaped likea duck's bill, which is flattened or tapering, but one of ordinary skillin the art will appreciate that the tip region may have other shapes inaccordance with the present invention.

The catheter 10 also contains a guide wire tip opening 22 that is ofsufficient size and shape to allow for the insertion of a guide wire(not shown) to position and guide the catheter. In the embodiment shownin FIG. 1, the guide wire opening 22 is at the distal tip 24 of thedistal end 14 of the catheter 10, however, one of ordinary skill in theart will appreciate that the position of the guide wire opening 22 maybe modified. Furthermore, applicant contemplates that the position(s)and size(s) of one or more of the openings 16, 18 may be varied toeffectively operate as described below.

In the practice of the methods of the present invention, this suctiontip region, when placed between anterior and posterior leaflets of themitral valve, is effective to draw the leaflets down flat against itssurfaces such that the leaflets are contiguous and immobilized. Thecatheter enters the mitral annulus from the a trial side.

Turning now to FIG. 2, the suction catheter 10 of FIG. 1 is shown havingbeen positioned in proximity of the mitral valve 26. The precisepositioning of the catheter 10 is effected by transesophagealechocardiography to place the catheter 10 in, at, or in proximity of themitral valve 26 such that the catheter may capture the anterior leaflet28 and posterior leaflet 30 of the mitral valve, while not contacting orharming the fragile chordal tendineae 32 that are attached to thepapillary muscles 34. In the embodiment shown in FIG. 2, the catheter 10has been placed slightly past the mitral annulus 27 and between theleaflets 28, 30; however the catheter may be placed at other locationsin, at, or in proximity of the mitral valve 26 while still being able tocapture the leaflets 28,30.

The catheter 10 is introduced into a patient's body percutaneously in amodified Seldinger technique via the venous vascular tree through thefemoral vein. The catheter 10 then is advanced up the inferior vena cavaand into the right atrium of the heart. The catheter 10 then crosses theatrial septum through a small atrial septostomy (created bycardiological techniques known in the art) to enter the left atrium ofthe heart. For example, a guide wire may be placed across the atrialseptostomy and the catheter 10 may then be threaded along the guide wireinto the left atrium. The catheter 10 then can be brought to rest at apredetermined locus in, at, or in proximity to the mitral valve 26. Forthis purpose, the catheter 10 may have a pre-formed or deflectable shorthook configuration at its tip region, as discussed further below withregard to FIG. 2A.

As shown in FIG. 2, the catheter 10 applies a suction force or reverseflow from its suction openings 16, 18 in a direction toward its proximalend 12 as indicated by the arrows within the catheter to create a forcenormal to the surface of the leaflets 28, 30 down against the flatsurface of the tip region. This suction force is of a magnitude that iseffective to capture the leaflets 28, 30 of the mitral valve 26. Thecapturing of the leaflets 28, 30 is preferably confirmed viatransesophageal echocardiography. If the suction has not captured theleaflets 28, 30, the suction may be stopped, the tip regionre-positioned against a first one of the leaflets, then the other one ofthe leaflets, and then the suction may be reapplied until such time astransesophageal echocardiography can confirm that the leaflets have beenproperly captured. In the FIG. 2 embodiment, the suction force hascaused both the anterior leaflet 28 and posterior leaflet 30 to adhereto the catheter 10 about midway between their edges, thus creating adouble orifice 36, 38 mitral valve 26. Data set forth in the above-citedarticle of Maisano, F. et al. in European Journal of Cardio-thoracicSurgery, 13 (1998), pages 240-246 confirms that this double orificemitral valve neither creates an impediment to ventricular filling, norcauses a significant pressure gradient across the mitral valve 26.

The positioning of the catheter 10 and the capturing of the mitral valve26 leaflets 28, 30 as described above can be advantageously performedpercutaneously without disrupting the normal functioning of the mitralvalve (i.e., the valve continues to open and close as the heart pumps)since the non-captured portions of the leaflets continue to move inresponse to flow. Also, by introducing the catheter 10 via the atrium,one avoids associated problems that would occur with a ventricularapproach to the valve 26. For example, due to the anatomy of the mitralvalve system, entry through the ventricle would only allow movement ofthe catheter to access to the mitral valve leaflets 28, 30 along acentral path directly between the leaflets, thus potentially limitingthe ability of the catheter 10 to effectively capture the leaflets, orto repair prolapse or flail located close to a commisure. The presentinvention, by approaching the mitral valve 26 via the atrium, allows forpositioning of the catheter at nearly any edge or central location ofthe mitral leaflets by virtue of the catheter 10 being free to maneuverat any position in the annulus of the mitral valve and to come to restwithin the valve or at either of the valve commisures. If necessary, thedimensions of the catheter 10 may be altered to more readily allow forparticular positioning and/or maneuvering of the catheter.

FIG. 2A shows a schematic vertical section through the heart, wherein afurther embodiment of the suction catheter 10 is positioned at themitral valve 26. In this embodiment, the catheter 10 has a distal regioncharacterized by a preformed U-turn with a base segment r of length Lthat defines a precise reach of the catheter tip 25 past the atrialseptum to position the distal tip length t within the mitral valveopening. The length L between corners a, b of the reach segment r placesthe suction gripping nozzle 22 at the medial commisure mc, the lateralcommisure lc, or centrally in the mitral annulus region ma. Thepredetermined contour with reach L may be implemented by forming thedistal end of the catheter with a catheter tube having sufficientstiffness to hold a pre-formed U-configuration, in which case astraightener may be inserted when initially placing the catheter 10, andwithdrawn as the catheter tip passes the septum S. Alternatively,various steering wire arrangements may be employed wherein one or moretension wires pass within the catheter interior are operated to form oneor more bends that position the suction tip at the desired spot in themitral valve 26.

In accordance with a further aspect of the invention, once the leafletshave been captured and the effectiveness of an intended suture point hasbeen verified to cure the prolapse or other defect, the immobilizedleaflets are permanently fastened at the identified site. This ispreferably accomplished using a percutaneously-inserted stapling device,which may, in different embodiments, be incorporated in the tipassembly, or may be guided to the immobilized site along a rail or guidewire.

Referring now to FIG. 3, a stapling device 40 is shown in addition tothe mitral valve 26 and catheter 10 of FIG. 2. The catheter 10 hascaptured the anterior and posterior leaflets 28, 30 of the mitral valve26 as described above with respect to FIG. 2. A flexible J-tipped guidewire 42 is then advanced through the suction catheter 10 and out of theguide wire opening 22, and the guide wire 42 is captured by anotherpercutaneous device and drawn out of the heart via the aortic valve. Theguide wire 42 then continues to the femoral artery, and is pulled into avascular sheath. The stapling device 40 is introduced into the femoralartery along the guide wire 42, and using the guide wire 42 as a rail,the stapling device is guided to the mitral valve 26 following thereverse path so that the jaws of the stapling device are positionedexactly at the immobilized site. This guide wire procedure allows thestapling device 40 to follow a smooth path to the leaflets 28, 30,without lateral movements that could damage the delicate web of chordaearranged in the left ventricle and extending from the leaflets.

Referring now to FIG. 4, the stapling device 40 has been advanced viathe guide wire 42 to a position wherein it may deliver one or more pins44 (two pins are shown in FIG. 4) across the mitral valve anterior andposterior leaflets 28, 30. FIG. 5 also shows the mitral valve 26, thesuction catheter 10 and the stapling device 40 in preparation for thedelivery of the staple pins to the leaflets by the stapling catheter.

FIG. 6 shows an enlarged view of one embodiment of such a staplingdevice 40 just before delivery of a pin 44 to the anterior and posteriorleaflets 28, 30. In this embodiment, the pin or staple 44 is atack-shaped rivet, having a head 44 a and a spreadable point 44 b. Theforce required to staple the pin 44 across the leaflets 28, 30 isgenerated by inflation, via a fluid inflation line 45, of a balloon 46that bears against an inner chamber 48 or wall of the jaws 41 a, 41 b ofthe stapling device 40.

Because of the path it follows to the mitral valve 26 (noted above withrespect to FIG. 3), the stapling device 40 is preferably implementedwith curved flexible tubes, preferably using a liquid or substantiallyincompressible fluid, to deliver the motive force to the distal tip.These tubes also allow for fluid to be delivered to inflate the balloon46 to provide the force to deliver one or more pins 44 to the leaflets28, 30 without stiffening the catheter wall or interfering with thecatheter contour or deflection of the tip.

Once the leaflets 28, 30 are immobilized in the proper location to bestapled (again confirmed by transesophageal echocardiography), theballoon 46 is inflated via the fluid inflation line 45. The inflation ofthe balloon 46 presses both walls of the inner chamber 48 and both jaws41 a, 41 b of the stapling device 40 inwardly, and spring 50 locatedwithin the inner chamber. The inflation of the balloon 46 forces the pin44 through the leaflets 28, 30, and spreads the point 44 b of the pin,thus riveting the leaflets together. Following the delivery of the pin44, the balloon 46 is deflated and the spring 50 recoils, thus freeingthe stapled leaflets from the stapling device 40. Another mechanism toeffect recoil of the stapling device is an additional balloon (notshown) in lieu of the spring 50. The additional balloon, when inflated,causes the jaws 41 a, 41 b of the stapling device 40 to separate.Following the delivery of the pin 44, the stapling device 40 may beremoved from the mitral valve area by reversing its path of insertion.

One of ordinary skill in the art will readily appreciate that theballoon 46 is not necessarily needed in order to deliver the pin 44across the leaflets 28, 30 and that other motive assemblies commonlyused in stapler mechanisms may be adapted to the illustrated accessgeometry. One of ordinary skill in the art will also appreciate thatmore than one pin 44 may be deployed (see, e.g., FIGS. 4 and 8), andalso that one or all of the one or more pins 44 may have a differentconfiguration than that which is described above.

The embodiment of FIG. 6 may optionally employ anterior and posteriorpadding elements 52, 54. The padding elements 52, 54 may be providedsuch that the one or more pin 44, once deployed, does not rest directlyagainst the fragile mitral valve 26 leaflets 28, 30 (see FIG. 7), andsuch that the point 44 b of the pin 44 is captured and secured by aprecisely preconfigured opening in the posterior padding element. In apreferred embodiment, the anterior padding element 52 is positionedbetween a first end 56 of the pin 44 and the anterior leaflet 28, whilethe posterior padding element 54 is positioned between a second end 58of the pin and the posterior leaflet 30. The padding elements 52, 54 mayalso have adhesive properties that help secure the pin or pins 44 to themitral valve. FIG. 8 depicts the mitral valve following deployment oftwo pins 44 and subsequent removal of the suction catheter 10 via thereversal of the path by which it was inserted as described above.

In addition to a transcardiac guide wire procedure wherein theimmobilized mitral valve leaflets are percutaneously fastened by astapling device deployed along the arterial tree, the present inventionalso contemplates a procedure and device for effecting such repairentirely from the atrial side. In that case, the necessary fasteningassembly is incorporated in the tip of the leaflet-grabbing catheter.

Turning now to FIG. 9, such an additional embodiment of a catheter 10′is shown in which mitral regurgitation repair is effected using a shapememory fastener 60. In this embodiment, a suction catheter 10′ is placedat or near the mitral valve 26 as described above with respect to theFIGS. 1-8 embodiment. The suction catheter 10′ also captures theanterior and posterior leaflets 28, 30 of the mitral valve as describedabove. Placement of the catheter and capture of the leaflets 28, 30 areagain confirmed and visualized by transesophageal echocardiography.

The suction catheter 10′ of FIG. 9 differs from the catheter describedin the FIGS. 1-8 embodiment in several respects. First, the catheter 10′does not contain suction ports in opposed flat faces in order toeffectuate suction, but rather contains an obstruction balloon 62 at itsdistal end 14, the balloon having a trailing fluid inflation line 66 toeffect inflation and deflation thereof and being placed so that itdefines lateral suction draw paths 69 (see FIG. 10) into the tip regionof the distal end of the catheter. As shown in FIG. 9, the balloon 62may be placed between the leaflets 28, 30 such that the flaps are drawntogether in the suction region.

The catheter 10′ has a tip assembly configured to contain a fastener 60of shape memory material. While inside the catheter 10′, the fastener 60is uncoiled (see FIG. 9). The shape memory fastener 60 may be movedwithin the catheter 10′ by a placement device 65, such as a plunger (seeFIGS. 10-11) or telescopic cylinder. The plunger 65 is configured topush the shape memory fastener 60 toward the distal end 14 of thecatheter 10′. The shape memory fastener 60 is then distally guided outof the distal end 14 of the catheter 10′ and its ends 61, 63 aredeflected outwardly, and forced to curve, by the shape of a pair ofguiding channels 64 a, 64 b at the rear face of the balloon 62 so thatthe fastener penetrates the opposed anterior and posterior leaflets 28,30. Specifically, a first end 61 of the shape memory fastener 60 isinserted into the anterior leaflet 28, and a second end 63 of the shapememory fastener is inserted into the posterior leaflet 30. Continuedpushing of the plunger 65 in a distal direction drives the shape memoryfastener 60 further through the leaflets 28, 30, and the first end 61 ofthe shape memory fastener 60 forms an anterior coil 68, while the secondend 63 of the shape memory fastener forms a posterior coil 70, while theremainder of the shape memory fastener straightens as shown in FIG. 12due to the presence of the balloon 62, which separates the leaflets.

Once the shape memory material 60 has secured the leaflets 28, 30, asverified by transesophageal echocardiography, the balloon 62 is deflatedand the catheter 10′ is removed. Following deflation of the balloon 62and removal of the catheter 10′, the central portion of the fastener 60reassumes a shape and forms a third coil 72 between the anterior coil 68and the posterior coil 70 as shown in FIG. 13. The formation of thisthird coil is not necessarily required and one of ordinary skill in theart will appreciate that the fastener may also form more than threecoils. The coils 68, 70, 72 draw the two flaps together, effectivelyriveting or suturing the valve closed at the site of the defect. Themitral valve 26 is shown in FIG. 14 following the removal of the balloon62 and catheter 10′.

The shape memory fastener as described above with respect to theembodiment depicted in FIGS. 9-14 is generally in the form of a rivet orother shape conducive to being contained within a catheter, and to beinginstalled with a simple ejection mechanism such as a plunger. Theillustrated shape memory fastener 60 includes at least two coils (theanterior coil and the posterior coil), and may form greater than threecoils. Exemplary shape memory materials include, but are not limited to,superelastic materials such as super elastic nickel titanium andstainless steel, and certain phase change thermal memory materials. Theillustrated fastener employs spiral coils, each lying in a planeperpendicular to the nominal axis of the fastener to provide a broadseating surface for each end of the fastener and a tightening retractionor shortening of the fastener length. However, other forms of fastenerdevices, including staples and shape memory fasteners of knownconfiguration, may also be adapted for catheter delivery at a suctiontip for the practice of the invention. Thus, for example, a singlehelical shape memory coil fastener may be carried in the catheter tipand ejected so as to wind through the opposed leaflets with its axisparallel to the plane of the junction. Furthermore, an additional lumenor ejection assembly may be configured to eject a dollop of a compatiblebioadhesive at the stapling site to enhance the fastening.

In addition to the embodiment described above with respect to FIGS. 9-14in which the shape memory fastener 60 is deployed by a plunger placementdevice 65, the shape memory fastener 60 may be deployed using otherplacement devices as shown in FIGS. 15-23 and as described below.

Referring now to FIG. 15, a system for deployment of a shape memoryfastener 60 is shown. This system, like the system described above withrespect to FIGS. 9-14, utilizes a partial obstruction balloon 62 todefine suction flows so as to capture the mitral valve leaflets 28, 30.The balloon 62 is inflated via a trailing fluid inflation line 66 suchthat suction paths 69 are defined and the leaflets 28, 30 are drawntogether as confirmed by transesophageal echocardiography . The balloon62 is then deflated and withdrawn, which causes the leaflets 28, 30 tocollapse around the shape of a catheter 10″.

A shape memory fastener 60 is contained within the catheter 10″ as is aplacement device 65′. Following deflation of the balloon 62, thefastener 60 is captured by the placement device 65′ and is moved withinthe catheter 10″ toward the distal end 14 of the catheter by distalpushing of the placement device within the catheter. In this embodiment,the placement device 65′ is a telescoping cylinder but placement devicesof other shapes such as a plunger blade may alternatively be used aslong as the placement device is sized and shaped so as to be able tomove within the catheter while still being able to capture and causedistal movement of the fastener.

As shown in FIG. 16, the distal pushing of the placement device 65′within the catheter 10″ causes the fastener 60 to move to the distal end14 of the catheter (at which the leaflets 28, 30 have been captured asdescribed above) such that the first and second ends 61, 63 of thefastener 60 approach the leaflets 28, 30. Continued distal pushing ofthe placement device 65′ within the catheter 10″ eventually causes theinsertion of the first end 61 of the fastener 60 into the anteriormitral valve leaflet 28, and the second end 63 of the fastener into theposterior mitral valve leaflet 30. As shown in FIG. 17, further pushingof the placement device 65′ within the catheter 10″ causes the insertedends 61, 63 of the fastener 60 to coil over such that each end alsoproceeds to penetrate and wind through the other leaflet. As before,these fasteners 60 may be formed of a superelastic or shape memorymaterial, and the ejection of the fastener is performed slowly to allowthe coil shape to wind through and suture together the two capturedtissue regions.

The distal pushing of the placement device 65′ within the catheter 10″is completed when the placement device reaches the distal end 14 of thecatheter or when the coiling of the fastener with respect to theleaflets 28, 30 has assured the closing of the valve at the site of thevalve defect as verified by transesophageal echocardiography, at whichtime the catheter and the placement device can be withdrawn. FIGS. 18and 19 show the mitral valve leaflets 28, 30 (FIG. 18) and the mitralvalve 26 (FIG. 19) in a vertical section along the AP plane, and a frontplan view, respectively, with the fastener 60 having formed three coilstherewithin. The number of coils that the fastener 60 may form withinthe leaflets 28, 30 can be greater or less than three subject to theconstraint that the wire must exert adequate holding force against themitral valve tissue. During installation, assurance is provided viatransesophageal echocardiography that the valve is properly closed atthe site of the valve defect.

Another alternate shape memory deployment system is shown in FIGS.20-23. This embodiment, like the systems described above with respect toFIGS. 9-14 and 15-19, utilizes a partial obstruction balloon in order toeffectuate suction to capture the mitral valve leaflets 28, 30. Theballoon is inflated via a trailing fluid inflation line such thatsuction paths 69 are defined and the leaflets 28, 30 are drawn together.The effectiveness of the intended suture site may be confirmed bytransesophageal echocardiography. The balloon is then deflated, so thatthe leaflets 28, 30 collapse around and conform against the shape of acatheter 10′″.

In this embodiment, however, instead of the fastener 60 being maneuveredvia a plunger placement device (see FIGS. 9-14) or a distally-pushedplacement device as shown and described with respect to FIGS. 15-19, theshape memory fastener 60 is threaded into the leaflets 28, 30 via theconcurrent distal pushing and rotation of a placement device 65″. Inthis embodiment, the placement device is a telescoping cylinder butother placement devices may alternatively be used as long as theplacement device is sized and shaped so as to be able to move within thecatheter while still being able to capture and cause distal movement ofthe fastener.

Referring now to FIGS. 20-21, a placement device 65″ is contained withina catheter 10′″. A shape memory fastener 60 has been partially threadedinto the wall of the placement device 65″such that the placement devicecan still freely move within the catheter 10′″, and also such that apredetermined portion 60 a, illustrating a penetrating free end, of thefastener is not threaded into the placement device. This predeterminedportion 60 a of the fastener 60 should be long enough to assure that itcan be inserted and advanced into, and maintained within a mitral valveleaflet 28, 30. It may be, for example, captured and deflected in agenerally forward direction by a guide groove in the interior wall ofthe catheter 10′″, or may simply project sufficiently forward topenetrate the adjacent captured valve tissue.

The placement device 65″is moved toward the distal end 14 of thecatheter 10′″ where the leaflets 28, 30 have been captured as describedabove and is simultaneously rotated. With continued distal movement androtation of the placement device 65″ within the catheter 10′″, thepredetermined portion 60 a of the fastener 60 penetrates either theanterior or posterior leaflet 28, 30 as can be confirmed bytransesophageal echocardiography and continues to wind through bothleaflets, forming a multi-turn coil, thus binding together the leaflets28, 30 as shown in exemplary FIG. 22.

The distal pushing and rotation of the placement device 65″ within thecatheter 10′″ is completed (at which time the catheters can bewithdrawn) when the placement device reaches the distal end 14 of thecatheter, and when the coiling of the fastener with respect to theleaflets 28, 30 has assured the closing of the valve at the site of thevalve defect as verified by transesophageal echocardiography. FIG. 23 isa front plan view of the mitral valve similar to that of FIG. 19 showingthe disposition of this fastener 60 having formed three coilstherewithin. The number of coils that the fastener 60 may form withinthe leaflets 28, 30 can be greater or less than three subject tomechanical design constraints and the mechanics of the valve tissue.During installation, adequate assurance is provided via transesophagealechocardiography that the valve is properly closed at the site of thevalve defect, and removal of that the catheter and placement device willnot cause the coils to be withdrawn from the leaflets.

The shape memory fastener 60 as described above with respect to theembodiments depicted in FIGS. 9-23 is generally in the form of a rivet,staple, wire suture or other shape conducive to being contained within acatheter, and to being installed with a simple placement device suchthose described above. Exemplary shape memory materials include, but arenot limited to, superelastic materials such as super elastic nickeltitanium alloy and stainless steel, and certain phase change thermalmemory materials or shape memory alloys.

Additionally, in lieu of or in conjunction with any of theabove-described embodiments, other methods and devices may be used toassure the proper repair of captured mitral valve leaflets. For example,a cardiac glue, such as that known in the art as Cardia, may be appliedto hold the mitral valve leaflets together. Also, cauterization may beused in order to hold the mitral valve leaflets together. Preferably,cardiac glue or cauterization, if used, are applied in addition to thesolid fastening element as described above.

One skilled in the art will appreciate further features and advantagesof the invention based on the above-described embodiments. Accordingly,the invention is not to be limited by what has been particularly shownand described, but is defined by the claims appended hereto andequivalents thereof. All publications and references cited herein areexpressly incorporated herein by reference in their entirety.

What is claimed is:
 1. An endovascular system for cardiac treatment,such system comprising: a first elongated catheter body adapted forpercutaneous insertion along the venous system of a patient to thepatient's heart, said catheter body including means for accommodating aguide wire; means for advancing a guide wire through said catheter bodyand along the arterial tree of the patient; a suction assembly disposedat a distal end of said catheter body, the suction assembly beingeffective to define negative flow into said catheter body along opposedsides thereof, whereby insertion of the catheter into the atrium withthe distal end of the catheter positioned in the mitral valve iseffective to draw opposed leaflets of said mitral valve together injuxtaposition for simulating an Alfieri leaflet stitch repair; and asecond, separate securing device adapted for percutaneous insertion andfor travel along said guide wire such that the securing device may bepositioned to secure to each other the opposed leaflets drawn togetherby the distal end of the catheter assembly.
 2. The device of claim 1,wherein the securing device includes an inflation element which, when ina substantially inflated state, is effective to cause the securingdevice to deploy a securing element to secure the opposed leafletstogether.
 3. The device of claim 2, wherein the inflation element is aballoon.
 4. The device of claim 2, wherein the inflation element isinflated via fluid delivery from a fluid source.
 5. The device of claim4, wherein the fluid source is located external to the catheter body. 6.The device of claim 2, wherein the securing element is selected from thegroup consisting of at least one pin, at least one staple, at least onefastener and at least one rivet.
 7. The device of claim 6, wherein eachof the at least one fasteners is made of a shape memory material.
 8. Thedevice of claim 6, wherein the rivet has a first substantially flat endand a second substantially pointed end.
 9. The device of claim 2,wherein the securing element has a first end and a second end, andwherein, once deployed, the first end is in communication with ananterior one of the opposed leaflets, and the second end is incommunication with a posterior one of the opposed leaflets.
 10. Thedevice of claim 9, wherein a first padding element is disposed betweenthe first end of the securing element and the anterior leaflet and asecond padding element is disposed between the second end of thesecuring element and the posterior leaflet.